Updated June 2026
The HackRF One covers 1 MHz to 6 GHz with both transmit and receive capability, and it remains one of the most versatile SDRs you can own. But its stock sensitivity and output power leave real performance on the table. The right external amplifier fixes both, and the wrong one can damage your SDR.
This guide tells you exactly which amplifier to use for your setup, what it costs, and the precautions that protect your HackRF.
Quick answer: which amplifier for your HackRF?
| Your use case | Recommended product | Key spec | Price |
|---|---|---|---|
| Receiving below 4 GHz (best sensitivity) | Ultra Low Noise Amplifier 10 MHz–4000 MHz | 0.65 dB noise figure | $42 |
| Receiving across the full 6 GHz range | Low Noise Amplifier 10–6000 MHz, USB Powered | Works 10 MHz to 8 GHz | $39 |
| Antenna-mounted LNA powered by the HackRF bias tee | Low Noise Amplifier 10–3000 MHz with Bias Tee & ESD Protection | 0.7 dB NF, powered over coax | $45 |
| Boosting transmit power to +20 dBm | High IP3 RF Low Noise Amplifier 50 MHz–6 GHz | +40 dBm OIP3, P1dB > +21 dBm | $48 |
| Strong nearby transmitters causing overload | Filtered LNAs (LNA + bandpass filter in one) | Band-specific | varies |
Read on for why each one fits, and for the precautions that will keep your HackRF alive.
One rule before anything else
The HackRF has a single shared port for transmit and receive. It is half-duplex: it can do one or the other, never both at once. That means an external amplifier only works if you dedicate your HackRF to one task. Set it up as a receiver with an LNA in front, or as a transmitter with a driver amplifier after it. Not both.
Using your HackRF as a receiver
The HackRF's own noise figure is over 3 dB. Noise figure is the spec that determines how weak a signal you can hear, and lower is better. Putting a quality low noise amplifier (LNA) ahead of the HackRF sets the noise figure of the whole system, which is why this is the single most effective upgrade for reception.
Best sensitivity up to 4 GHz
Ultra Low Noise Amplifier 10 MHz–4000 MHz 0.65 dB noise figure at 100 MHz. Gain of 23 dB at 100 MHz and 18 dB at 1 GHz. USB powered, so you can run it off your laptop. SMA-F connectors.
With a noise figure under 1 dB, this LNA improves your receive system's noise figure by more than 2 dB compared to the bare HackRF. That is a very noticeable jump in sensitivity on weak signals.
One important precaution. The HackRF's first internal amplifier has an input damage level of +13 dBm. With this LNA's gain in front of it, keep signals at the antenna below about −5 dBm. You will not encounter signals that strong over the air unless your antenna is essentially beside a transmitter. The realistic ways to cause damage are connecting a signal generator or a transmitter directly to the LNA with a cable. Don't do either without attenuation in line.
Full 6 GHz coverage
Low Noise Amplifier 10–6000 MHz, USB Powered Covers the HackRF's entire tuning range and operates to 8 GHz. Gain of 20 dB at 1 GHz, 12 dB at 6 GHz. 2.5 dB noise figure at 2 GHz. USB powered, SMA-F connectors.
The tradeoff for the wider frequency coverage is a higher noise figure than the 4 GHz model. If most of your listening is below 4 GHz, choose the first LNA; if you genuinely roam the full range, choose this one.
Mounting the LNA at the antenna (the best-performing setup)
For the lowest possible system noise figure, the LNA should sit at the antenna, not at the radio. Every metre of coax between your antenna and the first amplifier adds loss directly to your noise figure. The way to power a remote LNA is a bias tee, which sends DC up the same coax that carries your signal.
Good news: the HackRF has a built-in bias tee that supplies 50 mA at +3.3 V. Pair it with this LNA, which is designed to be powered over the coax:
Low Noise Amplifier 10–3000 MHz with USB, Bias Tee & ESD Protection 0.7 dB noise figure at 500 MHz. Accepts +3.3 V to +12 V over the RF cable, USB, or a DC header. ESD protection diode on the input guards against static damage from the antenna.
Using your HackRF as a transmitter
The HackRF tops out at about +15 dBm of output. If you want to reach +20 dBm (100 mW), use a high-linearity driver amplifier:
High IP3 RF Low Noise Amplifier 50 MHz–6 GHz +40 dBm output IP3 at 800 MHz and output P1dB above +21 dBm. Handles up to +24 dBm at its input without damage.
A note on naming: yes, this is an LNA being used on the transmit side. At these power levels that is exactly the right tool. Its very high linearity (that +40 dBm OIP3 figure) means it boosts your signal to +20 dBm without distorting it. With roughly 15 dB of gain at 1 GHz and an output P1dB of +21 dBm, keep the HackRF's drive level at or below about +5 dBm, using the HackRF's adjustable TX gain, so the amplifier stays in its clean linear region. Overdriving it will not cause damage below +24 dBm, but your transmitted signal will distort and splatter.
Check your local regulations before increasing transmit power. Most countries limit transmit power by band, and unlicensed transmissions can disrupt critical communications and draw serious fines. Know the limits for your band and licence class before you key up.
What about a real power amplifier? We get this question often, and our honest answer is that we do not recommend power amplifiers with the HackRF. The combination of broadband noise, spurious output, and licensing exposure rarely ends well. If your application genuinely needs more than 100 mW, talk to us about doing it properly with filtering and a measured setup.
The mistake that kills SDRs: amplifying without filtering
An LNA amplifies everything at its input, including the signals you don't want. Strong nearby transmitters such as FM broadcast, cellular base stations, and pagers get amplified right along with your target signal. At best they desensitize your receiver; at worst the combined power overloads and damages the HackRF's front end.
The fix is a bandpass filter that passes your band of interest and blocks everything else. You have two ways to do it:
- Add a Bandpass filter between the antenna and your LNA.
- Use a Filtered LNA, which combines the filter and amplifier in a single unit. One box, one cable, and the filter is exactly matched to the amplifier behind it. We build these for popular bands including ADS-B, GPS/GNSS, and the ISM bands.
If you are setting up for a specific signal type, the filtered LNA is the cleaner solution and usually the better value than buying the parts separately.
Recommended setups at a glance
- Weak-signal listening below 4 GHz: Ultra Low Noise Amplifier 10 MHz–4 GHz ($42) at the antenna end of a short coax run.
- General scanning across 6 GHz: Low Noise Amplifier 10–6000 MHz ($39) inline at the radio.
- Remote antenna installation: Bias Tee LNA 10–3000 MHz ($42) at the antenna, powered by the HackRF's built-in bias tee.
- Transmit experiments to +20 dBm: High IP3 LNA 50 MHz–6 GHz ($48) after the HackRF, with drive level kept near +5 dBm.
- Any of the above near strong transmitters: add a bandpass filter or step up to a Filtered LNA.
Not sure which fits your setup?
Every GPIO Labs amplifier is designed and tested by RF engineers, and our customers include research institutions, aerospace organisations, and a lot of serious SDR enthusiasts. If you are unsure which configuration suits your antenna, band, and environment, contact us and tell us what you are trying to receive or transmit. RF is what we do.